Conventionally, medical image diagnosis apparatuses that generate a medical image of a subject by using radiation, such as an X-ray competed tomography (CT) apparatus, a positron emission tomography (PET) apparatus, a single photon emission computed tomography (SPECT) apparatus, and a gamma camera, are known. Such a medical image diagnostic apparatus includes a radiation detector for detecting radiation, such as an X-ray or a γ-ray. In general, a radiation detector includes a detector pack including, as a component for detecting radiation, a detection element that detects radiation.